Nonimaging Optics - Compound Parabolic Concentrator

Compound Parabolic Concentrator

In the drawing opposite there are two parabolic mirrors CC' (red) and DD' (blue). Both parabolas are cut at B and A respectively. A is the focal point of parabola CC' and B is the focal point of the parabola DD' The area DC is the entrance aperture and the flat absorber is AB. This CPC has an acceptance angle of θ.

The Parabolic Concentrator has an entrance aperture of DC and a focal point F.

The Parabolic concentrator only accepts rays of light that are perpendicular to the entrance aperture DC. The tracking of this type of concentrator must be more exact and requires expensive equipment .

The Compound Parabolic Concentrator accepts a greater amount of light and needs less accurate tracking

For a 3-dimensional "nonimaging compound parabolic concentrator", the maximum concentration possible in air or in vacuum (equal to the ratio of input and output aperture areas), is:

where, is the half-angle of the acceptance angle (of the larger aperture).